#!/bin/python3
import sys
import os
import shutil
import datetime
import filecmp

USER_ID = os.getenv("USER")
SUBMISSION_BASE_DIR = "/shpc22/submission/{}/{}"
COMMAND_LIST =["status", "submit", "diff", "cat", "pull"]
HW_LIST = ["hw1"]
FILE_LIST = {
    "hw1": ["report.pdf", "convert.c"]
}

class bcolors:
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKCYAN = '\033[96m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'

def color_text(msg, msg_type):
    if msg_type == "fail":
        msg = bcolors.FAIL + msg + bcolors.ENDC
    if msg_type == "ok":
        msg = bcolors.OKGREEN + msg + bcolors.ENDC
    return msg

def print_usage_exit(msg=None):
    if msg:
        print(msg)
        print()
    print("Usage:")
    print("    shpc22-submit status")
    print("    shpc22-submit status [hw1|hw2|...]")
    print("    shpc22-submit [status|submit|diff|cat|pull] [hw1|hw2|...] filename")
    sys.exit(0)

def verify_hw_path_dir(hw, path):
    if hw not in HW_LIST:
        print_usage_exit(f"\"{hw}\" is not a valid homework")

    submission_dir = SUBMISSION_BASE_DIR.format(USER_ID, hw)
    os.makedirs(submission_dir, exist_ok=True)

    fname = path.rsplit(os.path.sep)[-1]
    if fname not in FILE_LIST[hw]:
        print_usage_exit(f"\"{fname}\" is not required in \"{hw}\"")
    return fname

def pull_file(hw, path):
    if os.path.exists(path):
        print(f"File \"{path}\" already exists")
        print("Do you want to proceed? (y/n)", end=" ")

        ans = input().rstrip().lower()
        if ans == "y":
            pass
        else:
            sys.exit(1)

    fname = verify_hw_path_dir(hw, path)
    submission_dir = SUBMISSION_BASE_DIR.format(USER_ID, hw)
    shutil.copy(f"{submission_dir}/{fname}", f"{path}")
    
def cat_file(hw, path):
    fname = verify_hw_path_dir(hw, path)
    submission_dir = SUBMISSION_BASE_DIR.format(USER_ID, hw)
    print("".join(open(fname).readlines()))

def diff_file(hw, path):
    if not os.path.exists(path):
        print_usage_exit(f"File \"{path}\" does not exist")

    fname = verify_hw_path_dir(hw, path)
    submission_dir = SUBMISSION_BASE_DIR.format(USER_ID, hw)

    if not os.path.exists(f"{submission_dir}/{fname}"):
        print_usage_exit(f"\"{fname}\" has not been submitted")

    if filecmp.cmp(f"{path}", f"{submission_dir}/{fname}"):
        print(f"{path}: ", color_text("SAME", "ok"))
    else:
        print(f"{path}: ", color_text("DIFFERENT", "fail"))

def submit_file(hw, path):
    if not os.path.exists(path):
        print_usage_exit(f"File \"{path}\" does not exist")

    fname = verify_hw_path_dir(hw, path)
    submission_dir = SUBMISSION_BASE_DIR.format(USER_ID, hw)
    shutil.copy(f"{path}", f"{submission_dir}/{fname}")

def status_file(hw, path):
    fname = verify_hw_path_dir(hw, path)
    submission_dir = SUBMISSION_BASE_DIR.format(USER_ID, hw)
    submission_path = f"{submission_dir}/{fname}"
    status = ""
    if not os.path.exists(submission_path):
        status = color_text("NOT SUBMITTED", "fail")
    elif os.path.getsize(submission_path) == 0:
        status = color_text("EMPTY FILE", "fail")
    else:
        m_time = os.path.getmtime(submission_path)
        m_date = datetime.datetime.fromtimestamp(m_time).strftime('%Y-%m-%d %H:%M:%S')
        fsize = os.path.getsize(submission_path)
        status = color_text("OK", "ok") + " / " + f"{fsize / 1000:.1f} KB" + " / " + str(m_date)
    print(f"  {fname:15}: {status}")

FUNCTION_LIST = {
    "status": status_file,
    "submit": submit_file,
    "diff": diff_file,
    "cat": cat_file,
    "pull": pull_file,
}

def status_hw(hw):
    if hw not in HW_LIST:
        print_usage_exit(f"\"{hw}\" is not a valid homework")

    print(f"{hw}")
    for path in FILE_LIST[hw]:
        status_file(hw, path)

def status_all():
    for hw in HW_LIST:
        status_hw(hw)

if __name__ == "__main__":
    if len(sys.argv) < 2 or sys.argv[1] not in COMMAND_LIST:
        print_usage_exit()

    user_submission_dir = "/shpc22/submission/{}".format(USER_ID)
    if not os.path.exists(user_submission_dir):
        print_usage_exit(f"You ({USER_ID}) are not registered to the course.")

    command = sys.argv[1]
    if command not in COMMAND_LIST:
        print_usage_exit(f"Unknown command: {command}")

    if len(sys.argv) == 2:
        if command == "status":
            status_all()
        else:
            print_usage_exit(f"Illegal usage: \"{sys.argv[1]}\"")
    elif len(sys.argv) == 3:
        if command == "status":
            status_hw(sys.argv[2])
        else:
            print_usage_exit(f"Illegal usage: \"{sys.argv[1]} {sys.argv[2]}\"")
    else:
        FUNCTION_LIST[command](sys.argv[2], sys.argv[3])